Image forming apparatus including duct provided with filter

Abstract

An image forming apparatus includes a duct, a filter provided inside the duct, a first fan provided on an upstream side of the filter in an exhaust direction and a second fan provided on a downstream side of the filter in the exhaust direction. A first mode operation containing a first operation in which the first fan sends air to the filter and a second operation in which the second fan sends air to the filter after the first operation is performed at least once, and then a second mode in which the first fan sends air in the exhaust direction is performed.

The invention claimed is: 
     
       1. An image forming apparatus comprising:
 a duct; 
 a filter provided inside the duct; 
 a first fan provided on an upstream side of the filter in an exhaust direction; and 
 a second fan provided on a downstream side of the filter in the exhaust direction, wherein 
 a first mode operation containing a first operation in which the first fan sends air to the filter and a second operation in which the second fan sends air to the filter after the first operation is performed at least once, and then a second mode in which the first fan sends air in the exhaust direction is performed, wherein 
 the first operation contains an operation in which the second fan sends air to the filter at wind force lower than the first fan, and 
 the second operation contains an operation in which the first fan sends air to the filter at wind force lower than the second fan. 
 
     
     
       2. The image forming apparatus according to  claim 1 , wherein
 a collection space is formed between the first fan and the filter and between the filter and the second fan. 
 
     
     
       3. The image forming apparatus according to  claim 1 , wherein
 in the first mode operation, a time where the first operation is performed and a time where the second operation is performed are the same. 
 
     
     
       4. The image forming apparatus according to  claim 1 , wherein
 the first mode operation is started during an image forming operation, and the second mode operation is started after a predetermined time elapses after a completion of the image forming operation. 
 
     
     
       5. The image forming apparatus according to  claim 4 , comprising an operation part which receives an operation to change the predetermined time. 
     
     
       6. The image forming apparatus according to  claim 1 , comprising an image forming part operated by a user and a human detection sensor disposed near the image forming part, wherein
 the first mode operation is started during an image forming operation in the image forming part, and the second mode operation is started when the human detection sensor no longer detects the user after a completion of the image forming operation. 
 
     
     
       7. The image forming apparatus according to  claim 1 , comprising:
 a fixing device which fixes a toner image transferred on a sheet to the sheet; and 
 a casing in which the fixing device is stored, wherein 
 the duct is formed along the exhaust direction from the fixing device to an outside the casing. 
 
     
     
       8. An image forming apparatus comprising:
 a duct; 
 a filter provided inside the duct; 
 a first fan provided on an upstream side of the filter in an exhaust direction; and 
 a second fan provided on a downstream side of the filter in the exhaust direction, wherein 
 a first mode operation containing a first operation in which the first fan sends air to the filter and a second operation in which the second fan sends air to the filter after the first operation is performed at least once, and then a second mode in which the first fan sends air in the exhaust direction is performed, and 
 the first mode operation is started during an image forming operation, and the second mode operation is started after a predetermined time elapses after a completion of the image forming operation. 
 
     
     
       9. The image forming apparatus according to  claim 8 , wherein
 a collection space is formed between the first fan and the filter and between the filter and the second fan. 
 
     
     
       10. The image forming apparatus according to  claim 8 , wherein
 the first operation contains an operation in which the second fan sends air to the filter at wind force lower than the first fan, and 
 the second operation contains an operation in which the first fan sends air to the filter at wind force lower than the second fan. 
 
     
     
       11. The image forming apparatus according to  claim 8 , wherein
 the second fan does not send air in the first mode, and 
 the first fan does not send air in the second mode. 
 
     
     
       12. The image forming apparatus according to  claim 8 , wherein
 in the first mode operation, a time where the first operation is performed and a time where the second operation is performed are the same. 
 
     
     
       13. The image forming apparatus according to  claim 8 , comprising an operation part which receives an operation to change the predetermined time. 
     
     
       14. The image forming apparatus according to  claim 8 , comprising an image forming part operated by a user and a human detection sensor disposed near the image forming part, wherein
 the first mode operation is started during an image forming operation in the image forming part, and the second mode operation is started when the human detection sensor no longer detects the user after a completion of the image forming operation. 
 
     
     
       15. The image forming apparatus according to  claim 8 , comprising:
 a fixing device which fixes a toner image transferred on a sheet to the sheet; and 
 a casing in which the fixing device is stored, wherein 
 the duct is formed along the exhaust direction from the fixing device to an outside the casing.